Candy Crush Soda Saga does it with microtransactions. The game is a puzzle in which you need to do something in a limited number of moves and on defeat screens

Candy Crush Soda Saga does it with microtransactions. The game is a puzzle in which you need to do something in a limited number of moves and on defeat screens there are notices along the lines of "420455 people bought extra moves to beat this level".